Visit our Popular Forums

Captin_Kirk · 03-05-2010, 19:08

Hello,

Originally my boat seems to have had two batteries in the battery compartment under the companionway stairs, however it seams that batteries are bigger now (Boat is a 1972) and there is no way 2 will fit there. I want to use the existing battery as the start battery and add two more for house power.

The question is where is the best place to put the bank? I don't want to use valuable storage space but also have no idea what is acceptable and what is not. I was thinking of building a battery box in the engine compartment. Is there an issue with this as long as they are enclosed and secured?

DeepFrz · 03-05-2010, 19:42

You want to keep them as low as possible. You may be able to get deeper batteries to keep the footprint smaller so you can get 2 batteries into your battery box.

I wouldn't put anything other than your start battery in your engine compartment. Most advice is to not have a battery in the engine compartment because of the heat, but they seem to survive in car and truck engine compartments.

rebel heart · 03-05-2010, 19:44

High, dry, and secure are the big ones. One thing to keep in mind is trim as well. A bunch of batteries will weight *a lot*, and if you're trimmed properly with them to port, moving them amidships might leave you a little tilted. May be no big thing, especially if you have a smaller bank. I shrank the bank a bit and ended up out of trim.

tallyhorob · 03-05-2010, 19:44

just keep in mind the gas produced when charging Lead acid Batteries. Need to make sure it vents

agrainofsand · 03-05-2010, 20:34

Who uses lead acid battries on a boat anymore? My boat had two new AGM batts when I bought it. I added 3 more, yes I had the room in the batt storage compartment in the engine room, now I have 600 AHs worth of Battery in two banks being charged by 360 watts of solar panel.

Tinkerer007 · 03-05-2010, 21:21

Quote:

Originally Posted by agrainofsand

Who uses lead acid battries on a boat anymore? My boat had two new AGM batts when I bought it. I added 3 more, yes I had the room in the batt storage compartment in the engine room, now I have 600 AHs worth of Battery in two banks being charged by 360 watts of solar panel.

Who uses lead batteries anymore. I have LiFePO4 batteries. Half the weight, twice the usable capacity. No Puekerts effect, fast charging. 10x the cycles of lead.

I replace two 100 AH batteries with one 200 AH LiFePO4 battery. Went from 60 usable AH to 140 usable AH and half the weight.

Bash · 03-05-2010, 21:26

Low. The further they are from the keel, the less they make sense.

Stillraining · 03-05-2010, 21:39

Quote:

Originally Posted by agrainofsand

Who uses lead acid battries on a boat anymore? My boat had two new AGM batts when I bought it. I added 3 more, yes I had the room in the batt storage compartment in the engine room, now I have 600 AHs worth of Battery in two banks being charged by 360 watts of solar panel.

Me..........

DeepFrz · 04-05-2010, 05:00

agrainofsand;
AGM batteries are lead acid batteries.

denverd0n · 04-05-2010, 06:14

Who uses lead acid battries on a boat anymore? Only about 90% of the cruisers out there.

Anzo · 04-05-2010, 06:29

My 4 AGMs are under the aft section of my C shaped settee, just in front of the bulkhead. Vented, compartmentalized, very nearly on centerline. 3 on/off switches mounted on bulkhead behind settee back. Fuses, buses lower on bulkhead.

hellosailor · 04-05-2010, 08:52

Kirk, you will have to make compromises. Wet lead acid is still arguably the most cost effective. AGM ends the acid splashing and venting problem. LiFePO4 is still cutting edge and gonna cost most dearly.

Sailboats work best when heavy things are LOW DOWN and CENTERED in the boat, out of the ends. But batteries work best with SHORT THICK CABLE RUNS.

So you decide how much battery you are going to buy, then see where you can locate them. If they're wet acid you need to keep them dry, can't locate them in the bilge, have to vent them. If they're big...you need to put them where you won't trip over them. Odds are you'll have fairly limited choices about where they can go.

Stillraining · 04-05-2010, 09:47

Quote:

Originally Posted by Bash

Low. The further they are from the keel, the less they make sense.

There ya go Bash...Your claim to fame and fortune..." Design a keel that is the battrie"

slomotion · 04-05-2010, 10:18

We had a similar issue on our 34' sloop. We wanted a large battery bank and there was no way we could fit it all in the original starboard battery compartment. Plus the boat already had a built in starboard list. And that's why we went with AGMs - one in the original compartment, two under the aft bunk, and one under the nav station - actually got rid of the list. You can mount them anywhere - upright or sideways. I have even seen them mounted in bilges - somehow I'm not ready for that. As hellosailor points out, the only real limiting factor is thick cable runs.